Hormones and Behavior

Definition

A hormone is something produced in the body that circulates in the bloodstream and then influences the activity of living cells that are far from where it was produced. Because hormones travel to their target tissue, they are sometimes referred to as signaling molecules. For example, estrogen is produced by the ovaries, but effects the functioning of cells in the heart, uterus, breast, liver, and brain. Any molecule produced [Page 443]in the body that travels to another tissue via the bloodstream for its effect is classified as a hormone.

Many hormones affect social behavior, often by directly influencing some aspect of brain function, although there are certainly other routes to influencing behavior. Hormones can only affect tissue that has receptors for them. If there is no receptor for a hormone in the brain, it cannot affect brain function. However, many hormones do have receptors in the brain. In social psychology, some of the most researched hormones include testosterone and estrogen (often called sex hormones), as well as vasopressin and oxytocin. Although it is often said that testosterone is the male hormone and estrogen a female hormone, is should be stated that all people have all of these hormones—it is just the amount that differs.

Hormonal links to human behavior are of interest to a variety of social psychologists but perhaps especially to those who are trying to understand topics like falling in love and sexual motivation, dominance hierarchies, and the reasons that differences exist in the behavior of men and women.

Testing for Hormone and Behavior Connections

Psychologists who are interested in understanding the role that hormones play in shaping human behavior rely on several types of research approaches. These would include animal research where hormone levels are experimentally altered, studies of humans with certain types of disorders that change the levels of hormones, direct measurement of hormone levels via immunoassay, and studies that take advantage of natural variations that occur in the levels of some hormones. With each approach, the psychologist is trying to see if changes in hormone levels relate to changes in behavior in a predictable way. For example, a social psychologist might be interested in the reasons that more females choose to major in psychology (study of human behavior), while more males major in engineering (study of mechanical objects). Although most psychologists would certainly agree that social attitudes play a major role in career choice, the potential role of biological differences could also be important. In fact, girls from a very young age appear to be more people oriented (playing with pretend people, drawing more people) and are shown to be more empathic and interested in feelings on a variety of indicators, while boys from a young age seem more drawn to nonliving mechanical objects and later show better spatial skills, such as the ability to visualize complex objects from a variety of angles. Because this sex difference is found all over the world, one might wonder if there is some biological basis for this difference. To test this, a psychologist might look at whether levels of hormones relate to differences in people orientation, empathy, or mental rotation skills.

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